The invention refers to a method for cutting a food, in particular, a loaf-shaped food, in which a loaf of the food is advanced toward a cutting device by means of a feed apparatus and cut into slices, strips or cubes by said cutting device.
The invention also refers to a cutting machine for cutting a loaf-shaped food that makes it possible to cut a loaf of the food into slices, strips or cubes and features a feed apparatus for advancing the loaf toward the cutting device during the cutting process,
A method and a cutting machine of the above-described type are generally known. As compared to the utilization of gripping hooks, fixing of the loaf by means of a vacuum gripper provides the advantage that the loaf itself remains undamaged because its surface is not permanently changed by the contact element of the vacuum gripper. In the known methods and cutting machines, the negative pressure is generated with the aid of so-called vacuum pumps. The negative pressure is transmitted from the vacuum pump to the interior of the contact element through a line. The contact element itself typically consists of a rubber collar of sorts that is intended to compensate for uneven areas and irregularities on the surface of the loaf due to its elastic properties in order to prevent the admission of air into the suction region of the rubber collar after the negative pressure is applied. During the cutting mode of the known machines, the vacuum pumps used typically operate continuously such that they do not have to be switched on and off between the cutting of two successive loafs, wherein the continuously operating vacuum pumps also compensate possible leaks in the region of the contact element that would allow ambient air to flow into the interior of the contact element and permanently maintain a sufficiently high negative pressure.
In order to solve the above-described problem, it is known to fit the contact element of the vacuum gripper with a blade that cuts into the loaf such that a seal is produced in the suction region. For example, DE 100 24 913 A1 discloses a cutting machine of the type described above, wherein the feed apparatus which comprises at least one “suction cup” that defines a negative pressure chamber, such that this negative pressure chamber is open toward the loaf. The suction cup features a blade-shaped edge that is intended to ensure a very tight connection between the suction cup and the product loaf.
U.S. Pat. No. 3,880,295 A also describes a cutting machine featuring a suction head with six suction regions that are arranged linearly adjacent to one another and equipped with blades that dig into the face to be fixed of a product being cut. In this case, each individual suction region is formed by an annular space between an inner blade and an outer blade extending concentric thereto. No suction region is arranged within the inner blade. The circular ring-shaped suction area of U.S. Pat. No. 3,880,295 A is thus sealed in each case towards the outside as well as towards the inside by means of a cutting edge.
Depending on the consistency of the surface of the loaf and the condition of the rubber collar of the contact element, however, leakage problems still occur in known vacuum grippers such that the vacuum is lost or the negative pressure is not sufficiently high for reliably fixing the loaf on the vacuum gripper. This leads to undesirable transverse displacements of the loaf during the advancing and cutting process that, in turn, result in an insufficiently accurate geometry of the produced slices, strips or cubes.
It would therefore be desirable and advantageous to provide an improved method for cutting a loaf-shaped food, as well as a corresponding cutting machine, in which the risk of losing or excessively reducing the vacuum in the contact element of the vacuum gripper is lowered.